1. Field of the Invention
The present invention relates to personal computer systems and more particularly to a split system personal computer which includes a media console containing user interactive components (e.g., CD-ROM drive, power switch) coupled to a processing unit having system components (e.g., central processing unit, memory, hard disk drive) via a cable and wherein an integrated drive electronics (IDE) direct access storage device in the media console is operated through a connection to an IDE controller on a planar board in the processing unit.
2. Description of Related Art
Personal computer systems are well known in the art. Personal computer systems in general, and IBM Personal Computers in particular, have attained widespread use for providing computer power to many segments of today's modern society. Personal computers can typically be defined as a desktop, floor standing, or portable microcomputer that is comprised of a system unit having a single central processing unit (CPU) and associated volatile and non-volatile memory, including all RAM and BIOS ROM, a system monitor, a keyboard, one or more flexible diskette drives, a fixed disk storage drive (also known as a "hard drive"), a so-called "mouse" pointing device, and an optional printer. One of the distinguishing characteristics of these systems is the use of a motherboard or system planar to electrically connect these components together. These systems are designed primarily to give independent computing power to a single user and are inexpensively priced for purchase by individuals or small businesses. Examples of such personal computer systems are IBM's Personal Computer AT and IBM's Aptiva.
Historically, a personal computer (PC) was a relatively large box that sat on top of a desk and contained all of the electronics--the processor, memory, IO devices, floppy disk drive, etc. This was known as the system unit and required a significant amount of desktop work space. The monitor was traditionally a cathode ray tube (CRT) that was placed on top of the system unit. The keyboard and (eventually a mouse) was placed in front of the system unit to provide for user input. Accordingly, these "desktop" computer systems combined all PC functions and accessibility in one enclosure on the desktop where significant space is required and noise sources are relatively close to the user. In addition, there was no way to compact the elements when the PC was not in use.
In order to reduce the clutter that a personal computer caused on the desktop, a tower design soon emerged that moved the system unit components into a tower form-factor that sat along-side the desk. The CRT now sat directly on the desk with the keyboard and mouse in front of it. However, this "minitower" type unit is typically placed on the floor where accessibility to drives (floppy and CD-ROM), power, and system activity (LEDs) is compromised and awkward. These two form factors (the "desktop" and "minitower" systems) have endured for quite some time with just various changes in the size, shape and color.
Recently, an additional form factor has been developed. The above related applications describe a split system personal computer form factor that significantly reduces the amount of desktop space needed, reduces noise on the desktop and provides easy accessibility to removable media drives. For example, the above-referenced application Ser. No. 08/721,650, describes a computer system that includes a media console coupled to a system unit with a multi-conductor cable. The media console contains at least one direct access storage device (e.g., floppy disk drive or CD-ROM drive). The system unit is separate from the media console and includes a microprocessor, a non-volatile storage device and a system power supply. The multi-conductor cable has one end coupled to the media console and another end coupled to the system unit for electrically connecting devices in the media console to devices in the system unit. The system unit has a first interface coupled to the expansion bus and the cable, and the console has a second interface coupled to the cable and the direct access storage device in the console.
The media console components connect to the system unit through the first interface and multi-conductor cable. The first interface can be an industry standard architecture (ISA) host card. This design makes the components appear as though they are directly connected to the ISA bus, so their remote location is transparent to operating system software. Because all the components are connected through the ISA bus, the performance of the integrated drive electronics (IDE) CD-ROM drive in the media console is limited by the ISA architecture and bandwidth. The cycle time for each 16 bit transfer from the IDE CD-ROM drive is about 875 ns, which yields a maximum transfer rate of about 2.3 MB/s. Not only are these CD-ROM data transfers relatively slow, but each data word must be transferred by a CPU instruction.
It is therefore desirable to provide a split computer system which can increase the performance of the CD-ROM in the media console.